ICT2014 Abstracts

The presentation will comprise a systematic information on clathrate formation, crystal structure, bonding and structure-property relations in multicomponent clathrate type I solid solutions with transition metals T: {Sr,Ba}₈T_x{Si,Ge}_46-x-y_y ( stands for a vacancy). Physical properties have been evaluated with respect to thermoelectric applications. Particularly the stability of clathrates of type I has been investigated in the systems with T = Ni, Pd, Pt, Cu, Ag, Au, Zn and Cd. Whereas Barium is able to form stable type I clathrates Ba₈T_x{Si,Ge}_46-x-y_y with all of these T elements, Strontium can only form clathrates with Copper and Zinc in case of a Germanium framework, but Strontium is unable to form stable clathrates of type I for Silicon-based frameworks. Density functional theory calculations were employed to shed light on the stability of the Ba,Sr clathrate solutions with Si- and Ge-cages. Ground state energy calculations can furthermore explain the phase relations found for the ternary systems Sr – {Ni, Cu, Zn} – Ge.